I've been looking into new front shocks for my truck as I've been told my vibration issue is caused by my Superlift shocks. I was going to adapt my Bilstein shocks but it doesn't look like it's going to work.

Rancho makes a shock for trucks with 1" to 2.5" of lift (#RS5374), but obviously a Superlift is 4". I looked up the specs for a couple stock replacement shocks and then what the Superlift 4" lift shocks are measured at....

(compressed/extended)
Rancho OE replacement - 13.75/18.25
Monroe OE replacement - 13.50/17.87
Superlift 4" shocks - 14.91/20.91

I can't find specs on the lifted Rancho shocks, but if they can go up to a 2.5" lift they've got to be in the 20.5" extended range which makes me think they might work on the Superlift! They're 3/8 thread unlike the Bilsteins so if it turns out they're not quite long enough I can always add in a 1" shock stud extension if I have to.

Anyone have any experience with the RS5000 shocks, or are they basically the same thing as the Superlift Superride shocks?
I can't find specs on the

 

I'm befuddled trying to figure how any shock absorber can cause vibration.

If the shocks are brand new, they will be stiff until they break-in (5-10,000 miles), and if you have any alignment or tire balance issues then the stiff shock would transmit that vibration more readily than a worn shock.

In summation, your shocks are not and cannot cause any vibration. They may transmit vibration, but cannot be the cause. Your 33" tires being out-of-round or imperfectly balanced are probably the cause of your vibration. Those 33's are pretty heavy.

FWIW, "stock" length shocks can be installed if you can fabricate (or buy) extenders. I did it to install Rancho RS 9000 shocks on my Superlifted Ranger. Of course, not very many people have access to a machine shop.

 

I will grab some of the rancho rsx9000's I have in the garage in the morning and can give you what they measure, one set is for a 2 - 4 " lift the other is a 6" lift. I have the model numbers with them so it will give you some numbers to reference. I only use the 5000 as a steering stabilizer but I will see what the one I have measures...

 

https://www.ranger-forums.com/f36/bi...5160-a-108379/

Maybe see if you can find some of the new bilstein 5160 they should have 4in lifted applications coming out and should help the ride immensity.

 

I forgot all about those! I'll have to look into it.

 

Thanks! Are they for a torsion bar truck?

 

Weak shocks will make the tire bounce, causing a vibration. I've heard this from a few people now who have experienced it, so it's worth a shot because new shocks fixed their problem! Do you have any pics of your extended RS9000 shocks?

 

My next door neighbor has a ranger ( 2004) with the superlift like you, same size tires as well (33"). He had the same problem last year after only driving 5000k on his superlift shocks.

His problem was the front tire had spun a bit on the rim throwing it out of balance causing a vibration between 80- 120 k/ph. Everyone he spoke to said shocks but he tried re balancing the tires first.

I'm not saying the shocks aren't your problem but unless you're certain, checking your tires balance may be a cheaper first attempt to fix the issue.

just my .02

either way I hope you get it fixed. I hate problems like this.

 

I agree, problems like this suck. I'm fairly certain it isn't a tire balance issue. It's done it pretty much since I installed the lift. It did it when I had the original 31" BFGs on brand new steelies and didn't go away when I put on different new wheels and tires. I'm still going to rotate the tires this weekend just to see if it does anything, and as I mentioned in the other thread I have a new front pair of Superlift shocks coming to see if I do just have a bad one.

 

Here is a photo of the stock length Rancho RS9000 alongside the Superlift shock. Unfortunately, I don't remember the length difference. For me, the bottom of the tube on the Superlift was close to hitting the clamp holding the CV joint rubber boot.



Next is a photo of the extender. It's just a short length of 3/4" rod stock turned down on the top to match the top of a shock. The other end is drilled & tapped to accept the top of the stock length shock (using LocTite). I've been using this setup for several years with no problems.

 

Thanks!! I'll be doing something similar if I do decide to get new shocks. Superlift is sending me a replacement set of fronts... because right now I just want to know if a different shock does fix the problem!